Alkali metal soap thickened lubricating oil



United States Patent ALKALI METAL SOAP THICKENED LUBRICATING OIL RobertHenri Metenier and J can-Baptiste Signouret, Notre-Dame-de-Gravenchon,Seine Maritime, France, assignors to Esso Standard Societe AnonymeFrangaise, Paris, France, a body corporate No Drawing. pplication April9, 1956 Serial No. 576,767

Claims priority, application France May 23, 1955 2 Claims. (Cl. 252-421)The present invention relates to improved lubricating greases, inparticular to lubricating greases which are stable at high temperaturesand which are resistant to mechanical stress and to oxidation andprocesses for preparing them.

Greases used at high temperature under diflicult working conditions, athigh speed and under heavy loads, must possess good resistance tomechanical stress, stability at high temperature and good resistance tooxidation to ensure satisfactory lubrication.

It is Well known that greases having an alkaline soap base, notablysodium soaps, dispersed in a highly refined V mineral oil having a goodviscosity index, are in general best suited for such purposes. The useof certain additional compounds with such greases, particularlypolyglycols and polyalkylene amines, act as peptizing agents, resultingin the effective dispersal of the alkaline soaps in the base oils, andwhich at the same time give the greases an excellent resistance tomechanical stress and a good stability at high temperatures. Aromaticamines such as phenylalpha naphthylamine, act as anti-oxidants whenincorporated in such greases.

The present invention relates to greases which have a good stability athigh temperature and under mechanical stress, a remarkable resistance tooxidation as well as other advantageous properties, which contain astabilizing agent obtained by condensing an alkylene oxide with aphenolic aminated resin.

The proportion of stabilising agent incorporatedin the grease is,according to the invention, between 01 and'5%, particularly between 0.5and 2% by weight based on the total grease composition.

The phenolic-amino-resins may be obtained by condensation of analkylphenol with, for example, formaldehyde or trioxymethylene in thepresence of ammonia.

The alkylene oxides or the polyoxyalkylenes capable of being condensedwith the phenolic-amino-resins preferably contain from 2 to 6 carbonatoms per molecule, and include polyoxides. They are preferably ethyleneoxide, propylene oxide, or butylene oxide.

The lubricating oils used as base oils in the greases of the presentinvention may be mineral or synthetic oils having a viscosity at 100 F.,preferably between and 433 centistokes and particularly between 18 and217 centistokes, and having a viscosity index within the range 0 to 160,and preferably greater than 60.

The metal soaps employed in the greases of the present invention arepreferably alkali or alkaline-earth metal soaps, particularly sodium orlithium soaps having the ability to form greases having a suflicientlyhigh drop point, and are present in the greases in grease-makingproportions, preferably between 3 to by weight based on the totalcomposition, and according to the type of grease which it is desired toobtain.

The acids used to obtain the grease-making soaps are preferably longchain fatty acids which may be saturated "ice or unsaturated and maybe'obtained, for example, from animal, marine or vegetable hydrogenatedoils and greases or by the oxidation of hydrocarbons, or they may betriglycerides.

Other addition compounds may be incorporated in the greases of thepresent invention, such as agents improving adhesion, anti-rust agents,and extreme pressure agents.

The greases in the invention may be prepared by the ordinary mixing,heating and cooling processes. Thus the fatty acid and thestabilizingagent described above may be added to all or part of the selectedlubricating oil, and after heating the mixture to a temperaturesufficient to obtain a homogeneous mixture, the saponification agent isadded and further heating takes place until homogenization andsaponification takes place. The grease is then poured on to trays andafter cooling, the blocks of grease so formed are worked up to thedesired consistency. The stabilizing agent may be added, if desired, atthe end of the heating, before the pouring, instead of with the fattyacid.

The use of stabilizing agents according to the present invention isparticularly efficacious for greases obtained from substantiallynaphthenic oils, or from synthetic oils of an aromatic character.

The present invention therefore comprises improved greases comprising alubricating oil, a grease-making proportion of a metal soap, and a minorproportion of a stabilizing agent consisting of the reaction product ofa phenolic-amino-resin with an alkylene oxide.

The following examples show the advantages obtained by the compositionof the present invention.

Two 'phenolic-amino-resins A and B were prepared by heating thefollowing mixtures for 6 hours at 130-150 F.

Resin A Resin B Octyljphenol 100 Dilutlon oil (viscosity of 50 0. 29 to38 centistokes) I 50 'lrioxymethylene p 2O 20 15 parts of ammonia wereinjected during 6 hours,

then heated for 2-hours at 2l2-220 F and finally for 3 hours at 300 F-In this way theresins A and B having the following characteristics wereobtained: 1

From the resin A the stabilizing agent C was prepared by reacting with15% of ethylene oxide at a temperature of 320356 F. for 15 hours.

In the same'way the stabilizing agent D was obtained by reacting 25% ofethylene oxide with resin B at a temperature of about 320v F. for 20hours.

The mode of operation used for the preparation of the greases in theexamples was derived fromthe recognised grease-making process called pancooling. It consists of putting all the ingredients in a tank,eliminating the water, heating until the melting of the mass in theneighbourhood of 390 F. The mass is then poured into trays and, afterre-cooling, the pans of grease are worked and homogenized.

A grease having the following composition was prepared as described, andlabelled Grease A.

Stearic acid, percent 15 Pure soda, percent 2.45

Mineral oil, percent 82.55

(Viscosity at 100 F.=32 centistokes. Viscosity index=l15.)

1.2% in weight of resin B was incorporated in grease A, the mixturebeing labelled Grease B.

EXAMPLE I 1% in weight of stabilizing agent C was incorporated in greaseA. 7

EXAMPLE II 4 bined nitrogen and then reacting said resin within therange of to weight percent, based on said resin, of an alkylene oxidehaving in the range of 2 to 6 carbon atoms at a temperature in the rangeof 320 to 356 F. 2. A lubricating grease composition comprising a majorproportion of a mineral lubricating oil, in the range of 3 to weightpercent of an alkali metal soap of a long chain fatty acid, and in therange of 0.1 to 5 Weight percent of a stabilizing agent consistingessentially of a reaction product formed by the condensation of a higheralkyl phenol, a trioxymethylene, and ammonia at a temperature in therange of 130 to 300 F. to obtain a phenolic-amino-resin containing inthe range of 15% in Weight of the stabilizing agent D was incop a 1.4 to2.2 percent combined nltrogen, and then reacting porated in grease saidresin withm the range or 15 to 25 Weight percent Table I shows theresults of the tests for the greases of ethylene Oxide at a temperaturein thelange 0f described above. to 356 F.

Table I Greases prepared as in Results Grease Grease Example Example A BI II Characteristics Drop point, F. 173 174 178 183 Flow test 100 g. ofgrease are placed on a Wire gauze cone 9 8. 7 0.9 0. 8 having a meshaperture of 149 microns (100 mesh) placed above a beaker and held 111position for 50 hours. The percent in weight of the oil separated isascertained. Penetration ASTM:

Worked 50 strokes 350 352 287 283 Stability as regards mechanicalworking. Worked 1,000 strokes 370 374 320 303 Worked 100,000 strokesFluid Fluid 345 325 Oxydizatlon test (Norma-Hofiman) Asample of 20 g. ofgrease is placed ina bomb 1 10 l 600 1 400 1 600 under an oxygenpressure of 7 kg./em. at 99 C. The time necessary to obtain a pressuredrop of 0.35 kgJcm. is measured.

1 Hours.

Table I shows that by incorporating stabilizing agents according to theinvention, improved greases are obtained, and which are superior to evengreases containing a phenolic-amino-resin.

What we claim is:

1. A lubricating grease composition comprising a major proportion of amineral lubricating oil, in the range of 3 to 30 weight percent of analkali metal soap of a long chain fatty acid, and in the range of 0.1 to5 weight percent of a stabilizing agent consisting essentially of areaction product formed by the condensation of a higher alkyl phenol, aformaldehyde and ammonia in an oil diluent at a temperature in the rangeof 130 to 300 F. to obtain a phenolic-amino-resin containing in therange of 1.4 to 2.2 weight percent com- References Cited in the file ofthis patent UNITED STATES PATENTS 2,340,036 Zimmer et al. Jan. 25, 19442,388,057 Herlocker et al. Oct. 30, 1945 2,410,911 Wasson et al. Nov.12, 1946 2,453,850 Mikeska et al. Nov. 16, 1948 2,454,541 Bock et al.Nov. 23, 1948 2,487,378 Roehmer et al. Nov. 8, 1949 2,499,365 De Grooteet al. Mar. 7, 1950 2,506,906 Smith et al. May 9, 1950 2,526,490 LieberOct. 17, 1950 2,612,474 Morgan et a1 Sept. 30, 1952 2,659,696 Neif Nov.17, 1953 FOREIGN PATENTS 745,161 Great Britain Feb. 22, 1956

1. A LUBARICATING GREASE COMPOSITION COMPRISING A MAJOR PROPORTION OF AMINERAL LUBRICATING OIL, IN THE RANGE OF 3 TO 30 WEIGHT PERCENT OF ANALKALI METAL SOAP OF A LONG CHAIN FATTY ACID, AND IN THE RANGE OF 0.1 TO5 WEIGHT PERCENT OF A STABILIZING AGENT CONSISTING ESSENTIALLY OF AREACTION PRODUCT FORMED BY THE CONDENSATION OF A HIGHER ALKYL PHENOL, AFORMALDEHYDE AND AMMONIA IN AN OIL DILUENT AT A TEMPERATURE IN THE RANGEOF 130* TO 300*F. TO OBTAIN A PHENOLIC-AMINO-RESIN CONTAINING IN THERANGE OF 1.4 TO 2.2 WEIGHT PERCENT COMBINED NITROGEN AND THEN REACTINGSAID RESIN WITHIN THE RANGE OF 15 ATO 25 WEIGHT PERCENT, BASED ON SAIDRESIN, OF AN ALKYLENE OXIDE HAVING IN THE RANGE OF 2 TO 6 CARBON ATOMSAT A TEMPERATURE IN THE RANGE OF 320* TO 360*F.